Stranger Than We Can Imagine (15 page)

The danger with using wave and particle models is that it is very easy to forget they are metaphors. To grasp the nature of the subatomic world we have to accept that the things in it are neither waves nor particles, as those words are commonly understood. We
need a different metaphor, one that recognises that the world at that scale runs on different or special laws.

The late science fiction author Douglas Adams once noted that ‘Nothing travels faster than the speed of light, with the possible exception of bad news, which obeys its own special laws.’ In tribute to Douglas Adams we will forget waves and particles and adopt news as our metaphor for describing the subatomic world, because there is no danger that we will take this literally.

Let us imagine a single unit of news, such as Vladimir Putin, the President of Russia, being photographed fighting a kangaroo. Such an event is unpredictable, in that it is not possible to say in advance when it is going to occur. All we can say, and both supporters and detractors of Putin will agree on this point, is that at some point the President is going to punch a kangaroo. That’s just the sort of person he is.

This news event is analogous to a subatomic event, such as nuclear decay. Nuclear decay is the process in which an atom of uranium or other unstable element spits out radiation. We can calculate averages and predict how much radiation a given chunk of uranium will emit over a certain time, but we are unable to say when the process will occur in a particular atom. Like Vladimir Putin fighting a kangaroo, it might happen right now, it might happen in half an hour, or it might happen in twenty years. There’s no way of knowing until it occurs.

This uncertainty was in itself a shocking discovery. Our universe, it was believed, ran under a strict process of cause and effect. It was no good having strict physical laws about what caused things to happen if nature was just going to do stuff whenever it felt like it. The realisation that an atom would decay for no reason at all, at a time of its own choosing, was profoundly unsettling. Einstein himself refused to accept it, famously remarking that ‘God doesn’t play dice with the world.’ Einstein believed that there must be a fundamental reason hidden somewhere deep within the atom to explain why it decays at certain moments and not others. No such mechanism has been found, and the scientific community is now
more in agreement with the English theoretical physicist Stephen Hawking, who has said that ‘God does play dice with the universe. All the evidence points to him being an inveterate gambler, who throws the dice on every possible occasion.’

But back to our news event.

Now that Putin has had a fight with a kangaroo, what will be the result? We can be certain that this single event will result in a wide range of media coverage. We could calculate this media coverage to a high degree of accuracy, assuming we knew factors such as the political affiliations of editors, bloggers, newspaper or television channel owners and the demographic target of the news outlets. Some coverage would be funny, some disgusted, some sensational and some irate. You could no doubt predict in advance what approach your favoured news source would take.

What, though, would be occurring in the period between the fight and the publication of the resulting news reports? There would be a lot of mental analysis about what had happened, and a lot of different potential interpretations would be considered. Some people might think that the fight made Putin a strong leader, and some would think that it made him a horrible person. Others might wonder if the fight had been faked for the cameras, or was representative of the current state of animal rights in Russia, or whether Putin was having a breakdown. Many would assume that the President was drunk. There would be people who thought that the whole incident was cynical media manipulation, designed to distract attention from an unrelated political scandal. There would probably be some people who entertain an elaborate conspiracy theory in which the kangaroo had been trained to throw the fight, or who would believe that they are oppressed by political correctness and should also be able to punch kangaroos whenever they feel like it. All these thoughts and interpretations would immediately be recorded on social media, alongside jokes, photoshopped images and fake accounts claiming to be Putin’s kangaroo.

These thoughts, and many more, make up a sea of potential truths which corresponds to the sea of potential states of a quantum
particle. These potential truths are not all mutually exclusive. It is entirely possible that the incident was planned media manipulation, and that Putin was also drunk. Many of the thoughts that follow the event are wrong, but there is no reason to think that only one is true.

There may be a lot of potential truths in that web of thoughts, but this does not mean that there is an infinite number. Vladimir Putin wrestling with a kangaroo would not generate the thought that carrots enjoy opera, for example. Events at the quantum scale may seem to be all over the shop, but it is not the case that anything goes.

The vast majority of these thoughts will not make it into the resulting media coverage. Russian journalists will self-censor because they believe it could be dangerous to express those thoughts in public, given Putin’s attitude to restrictions on reporting and freedom of speech. In the West that self-censorship is more typically brought about by the influence of lawyers. Lawyers look at the content of the coverage and reject anything that they could not defend in a court of law. Conspiracy theories about media manipulation, mental breakdowns and alcohol abuse dissolve away under the cold hard legal gaze. A wild and enjoyable cloud of potential interpretations collapses down into something more prosaic and solid. Or at least, they do for most news outlets.

In our analogy the lawyers represent the gaze of scientists, who peep into their experiment to see what is going on. In the time between the news event occurring and the resulting media coverage, all sorts of wild and exciting thoughts are flying around. It is only the arrival of the lawyers, or the curious gaze of a scientist, that puts an end to the fun. It is this act of observing that causes a cloud of potential to solidify into a measurable result.

What would happen if Vladimir Putin released a statement after the fight, but before the newspaper headlines, in which he shed more light on the incident? Imagine that in this hypothetical statement Putin confessed to undergoing therapy to deal with his crippling phobia of marsupials. This would, at a stroke, change the
face of the following morning’s front pages. Headlines that would celebrate Putin’s virile physicality would need to be rewritten. Anti-Putin headlines that questioned his suitability for office would be more extreme. Half of the possible results of the news event would wink out of existence before they even happened. Putin’s official statement would, like the gaze of lawyers, shut down speculation and potential headlines. The coverage of a news event is, therefore, not only affected by legal intervention and interpretation, but it also varies depending on exactly when that intervention occurs.

The subatomic world, ultimately, is a fuzzy sea of guesswork and speculation which only commits to becoming clear and definite when observed. The exact nature and timing of that observation can change what that foam of maybes coalesces into. We can’t directly see this fuzzy sea because our attempts to observe it cause it to solidify, just as we can’t read the minds of journalists but only see the finished stories they produce. The quantum world is like the fun your teenage children and their friends have in their room. You know it exists because you can hear their shrieks and laughter throughout the house, but if you pop your head around the door, it immediately evaporates and leaves only a bunch of silent self-conscious adolescents. A parent cannot see this fun in much the same way that the sun cannot observe a shadow. And yet, it exists.

The story of quantum physics is the story of people failing to find adequate metaphors for reality. My use of Putin fighting a kangaroo may have seemed like desperate floundering, but it is relatively sane in comparison to some explanations of the quantum world. The most famous of these inadequate metaphors is Schrödinger’s cat.

Schrödinger’s cat is a thought experiment suggested by the Austrian physicist Erwin Schrödinger in 1935. It was intended to be a
reductio ad absurdum
attempt to highlight the inherent absurdity of the prevailing interpretation of quantum physics. But quantum physics is rather impervious to
reductio ad absurdum
attacks, for they are usually more accurate than sensible descriptions.

In Schrödinger’s thought experiment, a cat is sealed in a box. The
box also contains some equipment which may, or may not, kill the cat during a certain time period.

Quite why Schrödinger thought it would be a good idea to bring the killing of cats into this is not clear. The fact that he considered it a reasonable analogy could provide some insight into how desperate scientists were to find adequate descriptions for the subatomic world. Or he may just have been more of a dog person. Psychological questions about his choices aside, we are left with a cat that we are unable to see. With the box sealed, there is no way to know if the cat is alive or dead. The status of the cat, at this point, is that it is just as much dead as it is alive. The only way to resolve the status of the cat is to open the box and have a look. This, the thought experiment suggests, is how the quantum world works.

Where this thought experiment fails as a popular metaphor is that non-scientists intuitively think the cat in the box must always be either alive or dead, even if we don’t know which until we take a look. The point that the metaphor is trying to get across is that the cat is both alive and dead at the same time. This unresolved contradiction is called a ‘superposition’. A superposition refers to a particle simultaneously existing in all its theoretically possible states at the same time, in the same way that Twitter would contain all the differing and contradictory perspectives on Putin fighting a kangaroo, before an observer came along and caused those potential states to collapse into something definite or legally defensible.

Cats which are both dead and alive are impossible to imagine, even if you read a lot of Stephen King, so Schrödinger’s thought experiment is flawed. It is trying to describe something that is difficult to imagine by saying that it is like something which is impossible to imagine. With metaphors like these, it is perhaps not surprising that quantum mechanics has a reputation for being incomprehensible.

The issue of metaphors and how much they influence our thinking was a problem that was being worked on in the 1920s by the Polish engineer and philosopher Alfred Korzybski. Korzybski was interested in how much of our understanding of the world was
coloured by the structure of our languages, such as the troublesome verb ‘to be’. In the grammar of a language such as English, it is not strange to say that one thing ‘is’ a different thing. We would think nothing of saying ‘Bertrand Russell is clever,’ for example, when the true situation we are trying to express is that ‘Bertrand Russell appears clever to me.’ By using words like ‘is’ we project our internal ideas, suspicions and prejudices onto the world around us, and then fool ourselves into thinking that they are externally real.

It is our ability to do this that allows us to lose ourselves in movies, and see fictional characters as real people rather than actors reading lines. But as Korzybski continually stressed, the map is not the territory. This was the point that the Belgian painter René Magritte was making in his 1929 painting
The Treachery of Images
, which depicts a smoker’s pipe over the sentence
‘Ceci n’est pas une pipe’
(‘This is not a pipe’). This would initially baffle its audience until it was pointed out that the image was not an actual pipe but a picture of a pipe, at which point the message of the painting would become obvious.

The difficulty of distinguishing between metaphor and reality, the map and the territory, is one which is particularly problematic in quantum physics. The concept of multiple universes was first dreamt up ‘after a slosh or two of sherry’ by the American physicist Hugh Everett III in 1954. Everett was looking for a different interpretation of the prevailing understanding of quantum mechanics, and he came up with a real humdinger. What if instead of the cat being alive and dead at the same time, he thought, the cat was alive in our universe but dead in a completely different universe? If a vast number of parallel universes actually existed, then everything which can happen does happen. Every quantum superposition would be a list of the possible alternatives in other universes. The act of observing quantum events wouldn’t cause clouds of potential to collapse into a single event, but would just remind us of what universe we are in.

The initial reaction to Everett’s idea was not good. Physicists tend
to favour Occam’s razor, the principle that when there are competing explanations, the simplest is more likely to be correct. Universes are big things, and conjuring one out of thin air in order to make sense of a living dead cat is quite a leap. As Everett’s idea required a phenomenal number of universes to ping into existence, he met with a lot of negativity.

Everett attempted to explain his idea to the great quantum physicist Niels Bohr in 1959, but the meeting did not go well. Bohr’s colleague Léon Rosenfeld would later write that ‘With regard to Everett neither I nor even Niels Bohr could have any patience with him, when he visited us in Copenhagen more than 12 years ago in order to sell the hopelessly wrong ideas he had been encouraged, most unwisely, by Wheeler to develop. He was indescribably stupid and could not understand the simplest things in quantum mechanics.’

Discouraged, Everett quit theoretical physics and spent the rest of his life as a defence analyst. He died suddenly in 1982, at the age of fifty-one. As per his wishes his ashes were dumped in the trash.

Although there was an increased interest in his ideas towards the end of his life, he did not live long enough to see how seriously they are now taken. There are many physicists who view the many-worlds interpretation, as it is now known, as the best description of reality that we have. According to the Oxford physicist David Deutsch, ‘The quantum theory of parallel universes is not some troublesome, optional interpretation emerging from arcane theoretical considerations. It is the explanation – the only one that is tenable – of a remarkable and counterintuitive reality.’